feat(question-classifier): add drag-and-drop sorting for topics list

[Minamiyama]

Summary

feat(question-classifier): add drag-and-drop sorting for topics list

• Implement topic sorting functionality using react-sortablejs
• Add draggable handle and visual feedback during sorting
• Update node internals after sorting to ensure proper rendering

fixes #22065

Screenshots

after-.mp4

Update

editor header also can be draggable

after-header-draggable.mp4

Checklist

• This change requires a documentation update, included: Dify Document
• I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.
• I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods

[Copilot]

Pull Request Overview

This PR adds drag-and-drop sorting for the question-classifier topics list using ReactSortable and ensures the node is re-rendered after reorder.

• Introduce handleSortTopic in use-config.ts to update the class list and call updateNodeInternals.
• Pass handleSortTopic through panel.tsx into ClassList.
• Replace static list rendering in class-list.tsx with ReactSortable and a draggable handle.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
web/app/components/workflow/nodes/question-classifier/use-config.ts	Added handleSortTopic callback and useUpdateNodeInternals import to support reordering
web/app/components/workflow/nodes/question-classifier/panel.tsx	Passed new handleSortTopic prop to the topics list component
web/app/components/workflow/nodes/question-classifier/components/class-list.tsx	Swapped wrapper <div> for ReactSortable, added draggable handle, and related state imports

Comments suppressed due to low confidence (1)

web/app/components/workflow/nodes/question-classifier/use-config.ts:171

• There are no tests covering the new handleSortTopic logic and re-render via updateNodeInternals. Consider adding unit or integration tests to verify that sorting updates the inputs and node internals correctly.

  const handleSortTopic = useCallback((newTopics: (Topic & { id: string })[]) => {

[crazywoola]

I have restored the UI with removing the extra padding and the handler.